According to Guenther (E. Guenther, "The Essential Oils", Vol. V, page 173, D. Van Nostrand Co. Inc., New York (1952), East Indian sandalwood oil "has been perhaps one of the most precious perfumery materials from antiquity down to modern times, and its popularity has shown no signs of waning." This oil is widely used in perfumery, and would be even more widely used except for its limited supply and high cost.
As is well known, a need exists for synthetic substances which can be used as sandalwood substitutes or extenders. It would be most desirable to be able to synthetically provide the major odorant compounds of the natural sandalwood oil, i.e. alpha-santalol and beta-santalol, but no commercially feasible route to these chemicals is known at this time.
It would be even more desirable to provide a synthetic compound which would have many of the desirable odor qualities of a fine East Indian sandalwood oil, yet not have the potentially labile primary allylic alcohol group present in the natural santalols. A compound which would be more resistant to acidic or oxidative decomposition as well as being base stable could be even more versatile than sandalwood oil itself.
There is no obvious explanation why only slight chemical changes should have such a dramatic effect on odor intensity other than to invoke the general unreliability of odor structure relationships. Why the addition or removal of a methyl group, the removal of a double bond or the mere moving of a methyl group would essentially destroy more than 90% of the odor intensity rather than merely cause subtle odor differences comparable to the subtle chemical differences cannot be explained by an theoretical concepts in the known art.
U.S. Pat. No. 4,052,341, issued on Oct. 4, 1977 provides a sandalwood type aroma imparting material having one of the structures:
TABLE I ______________________________________ Name Structure ______________________________________ 3-Methyl-5-(2,2,3- trimethylcyclopent- 3-en-1-yl)pentan-2-ol ##STR1## 3-Methyl-5-(2,2,3- trimethylcyclopentan- 1-yl)pentan-2-ol ##STR2## 5-(2,2,3-Trimethyl- cyclopent-3-en-1-yl) pentan-2-ol ##STR3## 6-(2,2,3-Trimethyl- cyclopent-3-en-1-yl) hexan-3-ol ##STR4## 4-Methyl-6-(2,2,3- trimethylcyclopent-3- en-1-yl)hexan-3-ol ##STR5## 3-Ethyl-5-(2,2,3- trimethylcyclopent- 3-en-1-yl)pentan-2-ol ##STR6## 3-Methyl-5-(2,3,3- trimethylcyclopent-3- en-1-(R)-yl)pentan-2-ol ##STR7## 3-Methyl-5-(2,2,3- trimethylcyclopent- 3-en-1-(S)-yl)pentan-2-ol ##STR8## 3-Methyl-5-(2,2,3- trimethylcyclopent- 3-en-1-yl)pent-3-en-2-ol ##STR9## ______________________________________
These materials are produced according to the reactions schemes:
TABLE II __________________________________________________________________________ ##STR10## ##STR11## (a) R.sub.1 = H, CH.sub.3, C.sub.2 H.sub.5 R.sub.2 = H, CH.sub.3 __________________________________________________________________________
East German Pat. No. 68,936 discloses for use in the sandalwood area a compound having the structure: ##STR12## Furthermore, Chemical Abstracts Volume 72, 125008b sets forth a genus for the East German 68,936 encompassing the following group of compounds: ##STR13## wherein R.dbd.CH.sub.2 OH, or --CHCH.sub.3 OH and R.sup.1 .dbd.H, CH.sub.3 or C.sub.2 H.sub.5
The 2,3-dimethyl-5-(2,2,3-trimethyl-3-cyclopentene-1-yl)-2-pentanol of our invention however, has unexpected, unobvious and advantageous properties in the sandalwood area not only insofar as the quality thereof is concerned but also insofar as the aroma strength and substantivity thereof is concerned. The "staying power" of 2,3-dimethyl-5-(2,3,3-trimethyl-3-cyclopenten-1-yl)-2-pentanol is unexpected, unobvious and advantageous.